• Title/Summary/Keyword: Mean residual life function

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A Study on Fatigue Analysis, Reliability and Life Expectancy of a Double Link Type Level Luffing Jib Crane (이중 링크 형식 수평 인입 집 크레인의 피로 해석, 신뢰도 및 수명 예측에 관한 연구)

  • 허철원;문덕홍
    • Journal of the Korean Society of Safety
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    • v.16 no.4
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    • pp.65-73
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    • 2001
  • This paper is a study on the fatigue analysis using BS5400 Part10(1980), code of practice for fatigue for a double link type level luffing jib crane which has been operated since the crane was built in 1985 at a domestic pier. South Korea. In addition, on the basis of the design lift due to fatigue analysis and the number of cracks detected from the nondestructive test the structural reliability and the residual life of the crane is predicted by evaluating the expected development of detectable fatigue oracle during the next five to ten years using Paris's Law for predicting fatigue crack growth and Gaussian probability density function to be reasonable for stress ranges below the mean values determined by laboratory tests. The statistical data used for the analysis of the structural reliability and life expectancy is given in the above referred code.

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Musculoskeletal and Functional Status of Adults with Cerebral Palsy (뇌성마비 성인의 근골격계와 기능 실태)

  • Yoon Myung-ok;Kim Chung-sun
    • The Journal of Korean Physical Therapy
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    • v.17 no.1
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    • pp.43-68
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    • 2005
  • The purpose of this study was to report the physical status of adult with cerebral palsy who live in local community areas including Seoul, Busan, Daegu in Republic of Korea at 2004. 202-individuals with cerebral palsy(140 male, 62 female; mean age 31.9 years; range 19 to 64 years) were surveyed. Measures included a 29-item self-reported health status measure focusing on musculoskeletal status and functional performances. Adult cerebral palsy required continuous management for musculoskeletal and ambulatory function through therapeutic approach. This survey is restricted to population who had cared in welfare center for cerebral palsy in local community, so it needs to investigate home-residual adults with cerebral palsy and the population in rural community. The results were as follows: 1. Participants reported that they had a limitation of a daily of life activity due to musculoskeletal pain($43\%$), there was significant differences between a limitation of a daily of life activity and the decreased ambulatory function(p<.05). 2. Thirty six point six percentile of participants had the decreased ADL function, it was significant related with the impaired body location(p<.05) 3. Thirty nine point one percentile of participants who can independently gait had the decreased ambulatory function, it was significant differences with the usage of ambulatory assistive devices(p<.05). 4. There was significant differences ambulatory function both the body region with impairment and a grade of disability(p<.05). 5. Sixteen point three percentile of participants could not ambulate any more, there was significant differences between a age and a point of time for non-ambulation(p<.05). 6. There was significant differences between ambulatory function and physical activity(p<.05).

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A study of comparative the mastication capability and life quality of elderly people using dentures or implants (의치 장착 노인과 임플란트 장착 노인의 저작능력 및 삶의 질 비교 연구)

  • Kim, Young-Sook;Jun, Boe-He
    • Journal of Korean society of Dental Hygiene
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    • v.11 no.5
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    • pp.629-636
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    • 2011
  • Objectives : The purpose of this study was to determine the effects of oral health on the quality of life of elderly patients with dentures or implants. It is our intention that through this analysis we can aid seniors in making the choice between dentures or implants, considering future masticatory function and the likely effects of this decision on the patients quality of life. Methods : This survey was conducted between November 1, 2010 and November 25, 2010, in Kyunggi-Do, whasung city. The research was carried out at one public health center, among elderly patients. 105 seniors were surveyed using the direct interviewing method, oral health related quality of life was measured by the Philadelphia Geriatric Center(PGC) Morale Scale. Collected data was examined using the SPSS 13.0 program, using frequency, mean, and standard deviation analysis, T-test and $x^2$ test. Results : The number of residual teeth for patients who have implants was $20.45{\pm}5.85$, while among those patients with dentures the number was considerably lower, $8.11{\pm}7.66$(p<0.05). The results of patients masticatory function, was $28.13{\pm}2.40$ for those with implants, and $25.35{\pm}4.15$ with dentures. The results were better for those with implants. Among implant patients overall satisfaction was rated $25.21{\pm}3.63$, higher than for those with dentures $20.20{\pm}6.79$(p<0.05). Quality of life was scored higher for patients with implants($12.76{\pm}2.61$) compared to those with dentures($10.47{\pm}3.52$)(p<0.05). The subjects masticatory function was highly related to the number of remaining teeth and greater masticatory function had a positive effect on patients quality of life and life satisfaction. Conclusion : Dental treatments such as dentures and implants will have a great influence on patients quality of life and life satisfaction. Implants can improve the oral health related quality of life and satisfaction and the general quality of life more than denture therapy.

A software reliability model with a Burr Type III fault detection rate function

  • Song, Kwang Yoon;Chang, In Hong;Choi, Min Su
    • International Journal of Reliability and Applications
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    • v.17 no.2
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    • pp.149-158
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    • 2016
  • We are enjoying a very comfortable life thanks to modern civilization, however, comfort is not guaranteed to us. Development of software system is a difficult and complex process. Therefore, the main focus of software development is on improving the reliability and stability of a software system. We have become aware of the importance of developing software reliability models and have begun to develop software reliability models. NHPP software reliability models have been developed through the fault intensity rate function and the mean value functions within a controlled testing environment to estimate reliability metrics such as the number of residual faults, failure rate, and reliability of the software. In this paper, we present a new NHPP software reliability model with Burr Type III fault detection rate, and present the goodness-of-fit of the fault detection rate software reliability model and other NHPP models based on two datasets of software testing data. The results show that the proposed model fits significantly better than other NHPP software reliability models.

Optimal Monitoring Frequency Estimation Using Confidence Intervals for the Temporal Model of a Zooplankton Species Number Based on Operational Taxonomic Units at the Tongyoung Marine Science Station

  • Cho, Hong-Yeon;Kim, Sung;Lee, Youn-Ho;Jung, Gila;Kim, Choong-Gon;Jeong, Dageum;Lee, Yucheol;Kang, Mee-Hye;Kim, Hana;Choi, Hae-Young;Oh, Jina;Myong, Jung-Goo;Choi, Hee-Jung
    • Ocean and Polar Research
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    • v.39 no.1
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    • pp.13-21
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    • 2017
  • Temporal changes in the number of zooplankton species are important information for understanding basic characteristics and species diversity in marine ecosystems. The aim of the present study was to estimate the optimal monitoring frequency (OMF) to guarantee and predict the minimum number of species occurrences for studies concerning marine ecosystems. The OMF is estimated using the temporal number of zooplankton species through bi-weekly monitoring of zooplankton species data according to operational taxonomic units in the Tongyoung coastal sea. The optimal model comprises two terms, a constant (optimal mean) and a cosine function with a one-year period. The confidence interval (CI) range of the model with monitoring frequency was estimated using a bootstrap method. The CI range was used as a reference to estimate the optimal monitoring frequency. In general, the minimum monitoring frequency (numbers per year) directly depends on the target (acceptable) estimation error. When the acceptable error (range of the CI) increases, the monitoring frequency decreases because the large acceptable error signals a rough estimation. If the acceptable error (unit: number value) of the number of the zooplankton species is set to 3, the minimum monitoring frequency (times per year) is 24. The residual distribution of the model followed a normal distribution. This model can be applied for the estimation of the minimal monitoring frequency that satisfies the target error bounds, as this model provides an estimation of the error of the zooplankton species numbers with monitoring frequencies.

The Effects of Autologous Blood Pleurodesis in the Pneumothorax with Persistent Air Leak (지속성 기흉에서 자가혈액을 이용한 흉막유착술의 효과)

  • Yoon, Su-Mi;Shin, Sung-Joon;Kim, Young-Chan;Shon, Jang-Won;Yang, Seok-Chul;Yoon, Ho-Joo;Shin, Dong-Ho;Chung, Won-Sang;Park, Sung-Soo
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.6
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    • pp.724-732
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    • 2000
  • Background : In patients with severe chronic lung diseases even a small pneumothorax can result in life-threatening respiratory distress. It is important to treat the attack by chest tube drainage until the lung expands. Pneumothorax with a persistent air leak that does not resolve under prolonged tube thoracostomy suction is usually treated by open operation to excise or oversew a bulla or cluster of blebs to stop the air leak. Pleurodesis by the instillation of chemical agents is used for the patient who has persistent air leak and is not good candidate for surgical treatment. When the primary trial of pleurodesis with common agent fails, it is uncertain which agent should be used f or stopping the air leak by pleurodesis. It is well known that inappropriate drainage of hemothorax results in severe pleural adhesion and thickening. Based on this idea, some reports described a successful treatment with autologous blood instillation for pneumothorax patients with or without residual pleural space. We tried pleurodesis with autologous bood for pneumothorax with persistent air leak and then we evaluated the efficacy and safety. Methods : Fifteen patients who had persistent air leak in the pneumothorax complicated from the severe chronic lung disease were enrolled. They were not good candidates for surgical treatment and doxycycline pleurodesis failed to stop up their air leaks. We used a mixture of autologous blood and 50% dextrose for pleurodesis. Effect and complications were assessed by clinical out∞me, chest radiography and pulmonary function tests. Results : The mean duration of air leak was 18.4${\pm}$6.16 days before ABP (autologous blood and dextrose pleurodesis) and $5.2{\pm}1.68$ days after ABP. The mean severity of pain was $2.3{\pm}0.70$ for DP(doxycycline pleurodesis) and $1.7{\pm}0.59$ for ABDP (p<0.05). There was no other complication except mild fever. Pleural adhesion grade was a mean of $0.6{\pm}0.63$. The mean dyspnea scale was $1.7{\pm}0.46$ before pneumothrax and $2.0{\pm}0.59$ after ABDP (p>0.05). The mean $FEV_1$ was $1.47{\pm}1.01$ before pneumothorax and $1.44{\pm}1.00$ after ABDP (p>0.05). Except in 1 patient, 14 patients had no recurrent pneumothorax. Conclusion : Autologous blood pleurodesis (ABP) was successful for treatment of persistent air leak in the pneumothorax. It was easy and inexpensive and involved less pain than doxycycline pleurodesis. It did not cause complications and severe pleural adhesion. We report that ABP can be considered as a useful treatment for persistent air leak in the pneumothorax complicated from the severe chronic lung disease.

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